Research On Operation Situation Evaluation Of Distribution Network Based On Big Data

As an important intermediate link between transmission network and users,the operation status of distribution network directly affects the power reliability and power quality.With the increasing scale of distribution network,its network structure is becoming more and more complex.Using scientific and reasonable methods to evaluate and analyze its operation situation is helpful to find out its weak links and provide corresponding guidance and basis for its construction and operation.On the basis of consulting a large number of relevant domestic and foreign literatures,the paper makes a study on the assessment and analysis of the distribution network operation situation.In this paper,the research on distribution network evaluation theory and index system is firstly conducted.The basic elements of the distribution network evaluation,the construction principles of the index system,the basic steps of the comprehensive evaluation,and several typical evaluation methods are introduced and analyzed.Aiming at the medium and low voltage distribution network,a set of practical evaluation index system of distribution network operation situation is established by using the current relatively mature analytic hierarchy process(AHP).It includes six kinds of indexes: voltage qualification rate,power supply reliability,operation failure,line loss,load rate and three-phase imbalance.And the meaning,calculation method,required data and data source of each evaluation index are introduced in detail.Secondly,based on the evaluation index system for the operation situation of the distribution network,the paper studies the operation situation evaluation ideas and related theoretical methods.The related methods of multi-source data processing are introduced,and the determination method of the single index scoring model is analyzed,and its adopts the fuzzy membership evaluation function curve to determine the scoring formula for each single index of the index layer.And the paper analyzes the setting method of index weight combining subjective and objective,its adopts the hierarchical analysis method to obtain the weight of each index in the standard layer,and adopts the combination of the AHP and the improved entropy weight method,with using the fuzzy synthesis method to obtain the comprehensive weights of the individual indicators in the indicator layer.And the paper introduces the overall process of operation situation evaluation of distribution network,and verifies the feasibility of the index system and method through the analysis of a practical example.Finally,the paper makes a research on the operation situation prediction ideas and related theoretical methods.Combined with the operation situation evaluation index system of the distribution network established in Chapter 2,the paper uses the fishbone diagram analysis method to sort out the predictable indexes,and then combines the short-term load forecasting and power flow calculation of the distribution network to calculate and analyze the extracted prediction indexes,and on this basis,a set of operation situation comprehensive risk assessment index system based on the utility theory is constructed for the overall operation situation early warning analysis.Then,the ideas of the operation situation prediction were enumerated,and makes a detailed description with a flowchart.Finally,the feasibility of the proposed operation situation prediction idea is verified by a practical example.